Effects of self-propagating synthesis reactant compact character on ignition, propagation, and microstructure

Journal Article · Wed Jul 01 00:00:00 EDT 1987 · Advanced Ceramic Materials; (USA)

DOI:https://doi.org/10.1111/j.1551-2916.1987.tb00085.x· OSTI ID:6074025

Rice, R W; Richardson, G Y; Kunetz, J M; Schroeter, T; McDonough, W J ^[1]

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1. Naval Research Lab., Washington, DC (USA)

Studies of reactions involving Ti to produce TiC, TiB{sub 2}, TiC + TiB{sub 2}, or 3TiB{sub 2} + 5Al{sub 2}O{sub 3} ignited at one end of test plates showed that reactant powder compact densities were a major factor in the reaction propagation rate along the plate, i.e., a maximum in propagation rate was observed at {approx}60 {plus minus} 10% of theoretical density. At higher densities, propagation rates not only decreased but terminated due to self extinction in some cases or failed to ignite and propagate, typically at {ge}90% of theoretical density. Both reactant particle size and shape can also affect results, i.e., compacts of large (200 {mu}m in diameter) Ti particles, Ti flakes or foil, or wires failed to ignite or had slower propagation rates. Also, the ignition and propagation rates of carbon fiber tows infiltrated with titanium metal powders depended significantly on the local thermal conductivity. However, overall propagation rates for a given range of reactant compact microstructures increased with the heat of the reaction involved.

• OSTI ID: 6074025
• Journal Information: Advanced Ceramic Materials; (USA), Vol. 2:3A; ISSN 0883-5551
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
TITANIUM BORIDES
CHEMICAL PREPARATION
MICROSTRUCTURE
TITANIUM CARBIDES
EXPERIMENTAL DATA
MEASURING METHODS
PARTICLE SIZE
REACTION HEAT
THERMAL CONDUCTIVITY
BORIDES
BORON COMPOUNDS
CARBIDES
CARBON COMPOUNDS
CRYSTAL STRUCTURE
DATA
ENTHALPY
INFORMATION
NUMERICAL DATA
PHYSICAL PROPERTIES
SIZE
SYNTHESIS
THERMODYNAMIC PROPERTIES
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
360201* - Ceramics
Cermets
& Refractories- Preparation & Fabrication